World's Smallest and Fastest Nanomotor Presages New Era of Medicine

In a major step towards developing miniature machines that could one day move through the body to deliver drugs or administer insulin for diabetics when needed, researchers have built the smallest, fastest and longest-running synthetic motor to date.

With all its dimensions under one micrometre in size, the nanomotor could fit inside a human cell and is capable of rotating for 15 continuous hours at a speed of 18,000 RPMs - the speed of a motor in a jet airplane engine.

The three-part nanomotor can rapidly mix and pump biochemicals and move through liquids, which is important for future applications, test of the nanomotor in a nonbiological setting revealed.

To test its ability to release drugs, the researchers coated the nanomotor's surface with biochemicals and initiated spinning.

They found that the faster the nanomotor rotated, the faster it released the drugs.

"We were able to establish and control the molecule release rate by mechanical rotation, which means our nanomotor is the first of its kind for controlling the release of drugs from the surface of nanoparticles," said Donglei (Emma) Fan, an assistant professor at the University of Texas in the US.

"We believe it will help advance the study of drug delivery and cell-to-cell communications," Fan added.

The team built and operated the nanomotor using a patent-pending technique that Fan invented while studying at Johns Hopkins University.

The technique relies on AC and DC electric fields to assemble the nanomotor's parts one by one.

In experiments, the researchers used the technique to turn the nanomotors on and off and propel the rotation either clockwise or counterclockwise.

The study appeared in the journal Nature Communications.